Prior art stretching devices for stretching and/or strengthening leg muscles have taken several forms, one of which forms requires that the user be seated and/or located in a prone position so that his legs move in a horizontal plane as taught for example in prior art U.S. Pat. No. 4,456,247 and 4,877,239.
U.S. Pat. No. 4,892,304 does suggest that the user assume an erect position, however one leg is secured against movement and although the other leg is moved in a vertical plane the leg is not kept straight in a kicking motion. The device of this patent immobilizes the user's torso and other leg. Such a situation results in a restrictive motion for the movable leg which does not resemble the kicking motion common to the martial arts.